US2766484A - Apparatus for use in depositing fluid or viscous materials on surfaces - Google Patents

Description

Ot. 16, 1956 J. c, SANDERSON 2,766,484

APPARATUS FOR USE IN DEPOSITING FLUID OR VISCOUS MATERIALS ON SURFACES Filed on. 17, 1952 2 Sheets-Sheet Oct. 16, 1956 J. c. SANDERSON 2,766,484

AP ATUSFOR USE IN DEPOSITINGFLUID VISCOUS MATERIALS ON SURFACES Filed Oct. 17, 1952 2 Shee ts-Sheet 2 APPARATUS FOR USE IN DEPOSITING FLUID OR VISCOUS MATERIALS ON SURFACES James Comber Sanderson, London, England, assignor to McCorquodale Colour Display Limited, London, England, a company of Great Britain Application October 17, 1952, Serial No. 315,290

Claims priority, application Great Britain October 24, 1951 2 Claims. (CI. 18-30) The present invention relates to apparatus for use in the deposition of fluid or viscous materials within confined areas on surfaces, and as examples may be mentioned the direct deposition of coloured pigments on sheets of paper or card, in the production of colour cards for eventual use in the selection of paint colours and the deposition of metalised inks on non-conducting surfaces for the production of printed circuits.

A machine adapted for the production of such articles is described in United States Patent to Battey No. 2,302,096, the described machine including a supporting platen for the sheets intended to receive the deposit and a matrix arranged to be engaged with the upper surface of a sheet supported on the platen, the matrix being formed with shallow cavities of rectangular or other predetermined shape and ports extending from the cavities through the body of the matrix and connected to reservoirs for the pigments, inks or other fluid materials to be deposited which are fed to the cavities under pressure.

The depth of the cavities is small, usually between 10 and 20 thousandths of an inch, and when the matrix is in fluid-tight engagement with the sheet and the deposit material caused to flow to the cavities a volume of deposit material approximately the equivalent of the cavity volume is deposited.

In cases where the sheets are of ordinary porous paper, the air originally entrapped within the cavities escapes through the pores in the paper so that the quantity of material deposited may be accurately related to the volumetric dimensions of the cavities and successive deposits are closely similar.

It is frequently necessary to deposit pigments and other fluid or viscous materials by a method employing such an apparatus, upon non-porous or only slightly porous sheets or bodies e. g. coated or otherwise relatively non-porous paper or card, plastics, mica, ceramics or the like and difliculty is encountered in obtaining uniform deposits or deposits of accurately predictable thickness due to the inability of air originally entrapped in the cavities to escape, this being particularly necessary in the case of printed circuits for example.

It is the object of the present invention to provide an improved apparatus of the kind indicated, with which the above mentioned dimculties are overcome so that a succession of volumetrically similar deposits can be produced.

For this purpose means are provided for evacuating the space within the cavities after the matrix has been brought into fluid-tight contact with the sheet on which the deposit is to be made.

The invention accordingly consists in an apparatus for use in depositing fluid or viscous materials on surfaces, comprising a platen or other support for the sheet or other body intended to receive the deposit, a matrix having one or a number of cavities in a surface thereof arranged to be engaged with the surface of a sheet or body on the support or platen in a fluid-tight manner, a port extending from each cavity through the body of the matrix and 2,756,484 Patented Oct. 16 1956 adapted for connection with reservoirs for the material to be deposited, means for controlling the admissionof material to be deposited from the reservoirs through the ports into the cavities and suction means adapted to withdraw air from the cavities after the matrix has made fluidtight engagement with the surface intended to receive the deposit and before the material to be deposited is admitted from the reservoirs through the ports to the cavities.

Several embodiments of the invention are illustrated by Way of example in the accompanyingdrawings in Which:

Fig. l is a view in sectional elevation of a part of a machine for use in depositing fluid or viscous materials upon paper or other sheets, and embodying one form of the present invention,

Fig. 2 is a view in sectional end elevation looking from the right in Fig. 1, and

Fig. 3 is a view of a part of Fig. l With parts shown in different positions.

Fig. 4 is a sectional end elevation showing an alternative construction, and

Fig. 5 is a sectional end elevation of still a further alternative construction.

Referring to the drawings, 1 represents a matrix formed by a metal block having shallow cavities 2 formed in the lower face, and 3 represents a platen arranged for rising and falling movement relative to the matrix 1 and to serve as a support for a sheet 4 of paper, card or other body of material and to hold said sheet 4 in sealing engagement with the boundaries of the cavities 2 of the matrix 1' when the platen 3 is in its raised position.

The upper surface of the matrix 1 is provided with a recess 5 opposite each of the cavities 2 in the face thereof and a port 6 extends from each upper recess 5 through the body of the matrix 1 to a cavity 2 in the lower face thereof.

In the recess 5 in the upper face of the matrix block 1 are mounted control valves of known form each comprising a guide sleeve 7 screwed at its lower end into the recess 5 and a tube 8 which is a sliding fit in the sleeve 7, the lower end of each tube 8 being closed and of conical form as shown at 9, the cone being adapted to seat in the upper end of the port 6 to shut off communication between the rccess 5 and the port 6 and therefore the cavity 2. The lower end of the tube 8 is provided with radial apertures it extending through its wall, and the upper end is connected through a flexible hose 11 to a reservoir (not shown) for the fluid material intended to be deposited.

The tube 8 is arranged to be raised and lowered in any convenient manner, and when moved to the raised position, as shown in dotted lines in Figs. 1 to 3, communication is established between the reservoir and the cavity 2 in the matrix 1, by way of the hose 11, the sliding tube 8, radial apertures 10, the recess 5 in the matrix block 1 the port 6 so that fluid may flow from the reservoir to deposit upon the sheet 4 patches of the material as defined by the boundaries of the cavities 2.

it is often desirable that the dimensions including the thickness of the patches of material deposited shall conform accurately to specific requirements, and for this purpose the depth of the cavities 2 in the matrix 1 has been suitably selected on the assumption that the cavities 2 become filled with the fluid material when the control valve 8 is opened. It has been found, however, that due to the body of air which is entrapped within the cavities 2 of the matrix when the sheet 4 is applied thereto, the cavities 2 in some cases become only partially filled with the deposit material.

In the case where the sheet 4 is an ordinary uncoated paper, the entrapped air can escape through the fibrous body of the paper, particularly if the deposit material is introduced to the cavities 2 under pressure, e. g. by air pressure applied to the reservoirs. When, however, the surface on which the deposit is to be made is that of an impervious or substantially impervious material, the entrapped air cannot escape from the cavities and ditficulty is experienced in obtaining deposits of a desired or uniform thickness.

In accordance with the present invention means are provided to enable the spaces in the cavities 2 after the sheet 4 or other body has been applied to the matrix 1, to be evacuated as a preliminary to the introduction of the deposit material into the cavities 2. Means for enabling such evacuation to be effected is illustrated in the drawings.

In the construction according to Figs. 1 to 3 the body of the matrix 1 is provided with a transverse bore 12 extending across the port 6 between the upper recess and the cavity 2. In this bore 12 a plug 13 is mounted for sliding movement, the said plug 13 being bored for the greater part of its length as shown at 14, and the bore 14 terminating at one end in a transverse aperture 15 adapted, in one extreme position of the plug 13 in the bore 14, to register with the lower part of the port 6, and being connected at the other end by a flexible tube 16 with a suction pump of any convenient kind (not shown).

The plug 13 at the end beyond the transverse aperture 15, is provided with a transverse bore 17 which in the other extreme position of the plug 13 in the bore 14 forms a connection between the upper and lower parts of the port 6.

The plug 13 with the bore 14 and aperture 15 constitute a suction valve for controlling the connection between the cavity 2 and the vacuum pump. Plug 13 and bore 17 constitute a flow control valve for controlling the connection between the cavity 2 and the reservoir.

A compression spring 18 is provided between a collar 19 fixed in the plug 13 and a fixed anchorage 20, and acting normally to urge the plug into one of its extreme positions as shown in full lines in Fig. 2 where the suction valve is open and the flow valve is closed.

With the suction pump operating and the plug 13 in the position shown in Fig. 1 and in full lines in Fig. 2, the sheet or other body 4 is applied against the matrix 1, and the transverse aperture 15 at the end of the bore 14 in the plug 13 being in register with the lower part of the port 6, air entrapped in the cavity 2 is withdrawn by the suction pump through the bore in the plug 13 and the pipe 16.

Thereafter the plug 13 is moved to its other extreme position in the bore 12, i. e. to the right in Fig. 2, in which the separate transverse hole 17 is brought into register with the upper and lower parts of the port 6.

The valve tube 8 may now be raised to permit the deposit material to flow through the open port 6 to fill the previously evacuated space in the cavity 2, and thereafter the valve tube is lowered to stop the flow of deposit material, and the platen 3 lowered to part the body 4, with the deposit thereon, from the matrix 1.

With an arrangement as described above the suction pump may if desired be allowed to operate continuously .and the movements of the plug 13 and the valve tube 8 may be efiected either by hand, or mechanically in appropriate timed sequence related to mechanically con- .trolled rising and falling movements of the platen 3.

In the arrangement shown in Fig. 4 a suction port 21 is provided, entirely separate from the port 6, said separate port 21 communicating at its lower end with the cavity 2 to be filled with deposit material by way of the valve controlled port 6 as in the previously described construction. The upper end of the separate port 21 is connected through a union 22 including a shut off cock 23, with a pipe 24 leading to a suction pump.

In this case, with the suction pump running and the cook 23 closed, the platen 3 is raised to apply the surface of the body 4 in sealing engagement with the matrix 1. The cock 23 is opened to apply suction to the cavity 2 at the lower face of the matrix 1 and is then closed, after which the valve tube 8 is lifted to uncover the port 6 to permit the deposit material to flow and fill the evacuated cavity 2 and thereby produce a deposit on the surface of the body 4 of dimensions related to the dimensions of the cavity 2.

The valve 8 is closed and the platen 3 lowered to part the body 4 with the deposit thereon from the matrix 1.

Another body 4 may now be substituted and the above described cycle of operations repeated.

In the arrangement according to Fig. 5 the matrix block 1 with cavities 2 in its lower face forms the lower wall of a closed air-tight box, the other walls being formed by a closed frame 25 and a top cover plate 26.

The valve arrangement for controlling the admission of deposit material from the reservoir to the cavities 2 in the matrix is generally similar to that in the previously described embodiments, the guide sleeve 7 for the movable valve tube 8 co-operating with a port 6 as before, extending across the depth of the box and being sealed in the plate 26 forming the top wall of the box, in an air-tight manner by means of a nut 27 and sealing washer 28.

A separate suction port 29 extends from each cavity 2 through the matrix block 1 and registers at its upper end with a tube 30 screwed into the upper face of the block and extending across the depth of the box.

The tube 30 is provided with radial apertures 31 in its walls spaced a short distance above the upper surface of the matrix block 1.

Within the tube 30 slides a fitted rod 32 extending upwards outside the box, the lower end of said rod being tapered for sealing engagement with a conical seating 33 formed within the tube 30 at a short distance below the radial apertures 31 in the tube. The several sliding rods 32 are connected at their upper end by bars or plates 34, whereby said rods may be moved vertically up or down in unison.

Similarly, the several vertically sliding valve tubes 8 controlling the flow of the deposit material to the cavities 2, are connected at their upper ends by bars or plates 35 whereby said tubes 8 may be moved vertically up or down in unison.

The interior of the box formed by the matrix 1, frame 25 and cover plate 26, is in communication through a flexible tube 36 with a suction pump.

With this form of the apparatus suction may be applied continuously to the interior of the box.

With the valve tubes 8 and the sliding rods 32 in their lowered positions, no fiow of deposit material is taking place and communication between the interior of the box and the port 29 is interrupted by the engagement of the conical lower end of the rod 32 with the conical seating 33 at the upper end of the port 29.

The sheet or other body 4 is brought into sealing engagement with the underside of the matrix 1 and the sliding rods 32 are raised to lift their lower ends from the seatings 33 and by a distance to uncover the radial apertures 31 in the walls of the tubes. The ports 29 are thus put into communication with the interior of the box so that suction takes effect to remove air from the cavities 2. The sliding rods are now lowered to seal the upper ends of the ports 29, and the valve tubes 8 momentarily raised to permit the deposit material to flow and fill the cavities 2, and when the valves 8 have been restored the platen 3 is lowered and the body 4 may be removed with the patches of deposit material of the required dimensions thereon.

With known apparatus of the kind referred to above it has been the practice to employ pressure, e. g. from a source of compressed air, upon the surface of the fluid or viscous deposit materials in the reservoir or reservoirs, to feed the materials to the cavities.

By the use of the apparatus according to the present invention, such feed pressure may, when using at least some fluid or viscous materials, be dispensed with. This offers the advantage that the reservoirs may be simple open containers to which ready access may be obtained for the purpose of observation, refilling, stirring and so on.

I claim:

1. An apparatus for use in depositing fluid or viscous materials on surfaces in a thin layer of predetermined thickness and over a predetermined area, comprising a support for a body intended to receive the deposit on its surface, a matrix having a cavity in a surface thereof adapted to be engaged with the surface of the said body in a fluid-tight manner, the depth and area of the opening of said cavity in said surface conforming with said predetermined thickness and predetermined area and the depth of said cavity being of small dimension such that flow of fluid therein will trap air in portions of the cavity, said matrix having a materials supply conduit formed therein and extending from said cavity through the body of the matrix and adapted for connection with a reservoir for the material to be deposited, said matrix having a valve cavity formed therein and intersecting said supply conduit, a movable valve member mounted in said valve cavity and being movable from a first position in which said supply conduit is cut ofi from the matrix cavity to a second position in which the supply conduit is connected to the matrix cavity, a suction conduit connected with said valve cavity and controlled by said valve member to apply suction to said matrix cavity in the said first position of said valve member, an operator member for said valve member, and spring means acting upon said operator member to normally hold said valve member in its first position.

2. An apparatus for use in depositing fluid or viscous materials on surfaces in a thin layer of predetermined thickness and over a predetermined area, comprising a support for a body intended to receive the deposit on its surface, a matrix having a cavity in a surface thereof adapted to be engaged with the surface of the 'said body in a fluid-tight manner, the depth and area of the opening of said cavity in said surface conforming with said predetermined thickness and predetermined area and the depth of said cavity being of small dimension such that flow of fluid therein will trap air in portions of the cavity, said matrix having a port formed therein extending from said cavity through the body of the matrix and adapted for connection with a reservoir for the material to be deposited, a flow control valve to initiate and terminate flow of the material to be deposited from the reservoir to the cavity by Way of said port, a suction conduit also extending through the body of the matrix and traversing the said port, a suction control valve member comprising a rod having a flow passage and a separate suction passage therein, said rod being arranged for sliding movement in said suction conduit within the body of the matrix be ween two positions in one of which the end of the said port adjacent the cavity is in communication with said separate suction passage in said rod and isolated from the passage for deposit material controlled by the said flow control valve and in the other of which the end of said port adjacent the cavity is isolated from said separate suction passage in said rod and is in communication through the said flow passage in said rod with the passage for deposit material controlled by the said flow control valve.

Reterences Cited in the file of this patent UNITED STATES PATENTS 2,302,096 Battey Nov. 17, 1942 2,335,528 Neils Nov. 30, 1943 2,474,567 Applegate June 28, 1949 2,516,908 Pottle Aug. 1, 1950 2,581,253 Ellis et al Jan. 1, 1952 FOREIGN PATENTS 618,961 Great Britain Jan. 1, 1952

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